Grinding wheel



' Dec.. 2, 1930. 'r. LARSSON 1,783,728

GRINDING WHEEL Filed June 30, 1927 Zjmento'c Thurs L arss o n anion mg E Patented Dec. 2, 1930 made up of segments ments are. liable segments secured or they have features.

, UNITED STATES PATENT OFFICE rnnnn LARSSON, or WORCESTER, mssacnusnr'rs, assmnon TO Noaron comm. or WORCESTER, yassacnusnrrs, A CORPORATION or 1massacrmsmurs GRINDING WHEEL v I 2 Application filed June so This invention relates to grinding wheels and more particularly ,to a grinding wheel grains. v Y

It has not been found feasible to make large grinding wheels of a single monolithic structure since such wheels, when rotated rapidly,

are liable to burst under the stresses set up by centrifugal force and the grinding opera tion. Such a wheelmay, however, be made of segments mounted on a suitable support and adjustably and rigidly fastened. in posi-' tion. There are, however, various problems connected with the manufacture and use of such a wheel since-the fragile abrasive segto break from'their settings unless held very securely in position. Various types of clamping devices have. been provided heretofore for securing such segments on a support, but these have plicated in structure and diflicult to handle and assemble, or they have been so large as to be in the way during the grinding operation had various other objectionable It is accordingly the primary object of my invention to overcome such diificulties and to provide a grinding wheel made up of abrasive 'ri 'dly on a support and which may-be rotated under the ordinarily grinding conditions without danger of breakage. I It is a further object to provide a grinding wheel mounting capable of securing an abrasive annulus rigidly but removably to a rotatable support.

With these and other objects in view as will be apparent to one skilledin theart',

my invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto. a Referring to the drawings which illustrate one embodiment of my invention:

Figure lis a side elevation of a segmental grinding wheel;

Fig. 2 is a perspective view of one of the segments removed from its fastenings;

Fig. 3 is a-fra entary sectional view on thehne3.3of'l i g 1*snd m of bonded abrasive either been com-' at a high rate of speed 1927. Serial No. 202,673.

Fig. 4 is a similar fragmentary sectional view on the line 4- 4 of Fig. 1.

In accordance with the embodiment of .my invention illustrated in the drawings, a segmentalwheel may be made of a number of abrasive segments so shaped and arranged as to form an annulus havin an outer cylindrical surface and two side aces and an inner portion arranged to be engaged by clamping and support plates. These'segments may be united into an integral body b a suitable cementitious material such as a w melting metal. The preferred arrangement for rotatably supporting an abrasive annulus, whether-made of segments or of ,a monolithic abrasive structure, comprises clamping ni'emmg portion of the annulus may be reduced in size. In the present construction,

I propose to formthe clamping shoulders on lugs or columns of abrasive which project outwardly like pilasters from the side faces of the segments. g This insures having the maximum amount oft-abrasive between the clamping plates and consequently a stronger wheel structure, than would be had if these shoulders were located within rooves or recesses. I 1

- Referring more particularly to the draw,- ings, showing a wheel made of segments mounted on two plates, the abrasive segments may be shaped as shown in Fi 2, each part having an outer convex surface 0 which forms a portion of the peripheral cylindrical in a wheel of this faces 13 preferably form radial. planeg in the wheel. The inner portion 14 of segment is shown reduced in size so the clamping plates ma lie within the planes formed by the side aces 12 of the segments when assembled as an annulus.

' The clamping plates15 and 16 which serve to support the abrasive ring, are illustrated as made of disks of metal provided with central apertures 18 arranged to be suitably mounted on a grinding wheel spindle, but it will be understood that these plates may be suitably shaped. and arranged for attachment to any rotatable device as may be desired for mounting the abrasive annulus. These plates may be secured together by screws 19 or other suitable means. a v In order to form clamping'shoulders which may be engaged by the plates 15 and 16, I preferably provide the annulus with a projiecting portion of abrasive which in the present instance isshown as made up of spaced lugs or pIilasters 20 projecting rom each side face. f the wheel is made of individual segments, each is provided with one or more lugs on one or both side faces. These mayproject to substantially the planes of the side faces engaged by properly sha ed flanges on the clamping plates but in or er that the clamping plates may lie within these planes, it'is preferred that the plates be cut away to pro vide a series ofspaced grooves or openings 22 into which the lugs 20 may be inserted. The top shoulders 24 of the lugs are adapted to be engaged by shoulders 25 on the inner faces of the openings 22 cut in theplate, and in order to provide a wedging action between the clamping plates and the lugs, the shoulders 24 on the abrasive body are made beveled or sloping, and the shoulders 25 on the plates are shaped to fit the same, whereby upon drawing the clamping plates 15 and 16 together by means of screws 19, thesegments are forced inwardly toward the center of the wheel.

Since the abrasive material is relatively fragile, as it is ordinarily made of abrasive grains bonded by vitrified ceramic materials, any severe clamping pressure on the lugs is likely to be unevenly distributed and to crack the abrasive body. Hence, 1 preferably provide the clamping shoulders of the segments with shoes 26 which may be made of ametal, such as babbitt or zinc; smooth faces sloping as desired to engage and fit snugly the clamping shoulders of the plates. Theseshoes may be suitably formed in position as by casting the molten material on the shoulders. s V The abrasive annulus is supported on its peripheral surface 11 and to this end one or both of the clamping plates may be provided with a peripheral, surface on which the annulus rests. The inner peripheral faces 11 of the segments are preferably provided with shoes 28 which have smooth faces arranged to fit accurately against the supporting surface on the mount. It will be understood that the segments themselves may be shaped so smoothly and accurately as to provide for this purpose, or a layer of proper material may be inserted between the segments and segments, 12. These shoulders may bev the clamping p The shoes have supporting or the clamping surfaces of the plate. However, the shoe 28 is desirable for many sizes and types of wheel. In the form illustrated the annulus is arranged to rest upon and be firmly clamped against the peripheral cylindrical surfaces 29- and 30 on the clamping plates 15 and 16. The inner faces 31 and 32 of the plates 15 and 16 (Fig. 3) are so shaped that they will lie close to the side faces of the segment but they preferably will not contact therewith, it being desired that the only faces of the plates 15 and 16 which contact with the segments be those which engage the metal shoes thereon.

After the segments have been mounted in position on the clamping plates and in order to make an integral and unitary structure of the wheel, I prefer to place a filler in the crevices 35 between the radial faces 13 of the and a suitable filler for this pur pose is a cementitious material such as sulfur or a low melting metal which is poured in sufiiciently hot to run down into the crevices and permeate the surface pores of the segments. This filler serves to unite the segments into a unitary structure and to make a solid wheel which may be employed with various types of supports or clamping plates. This filling material may be flowed into placev between the se ments either before or after I ates have been put into p osition, but if the filler is placed between the segments beforehand, then I thereby form an abrasive annulus which may be shipped as such without the clampin plates and may be mounted between the c amping plates at the point of use. The annulus, as m'anufactured and ready forshipment, has not only the filler and cementing material between the segments, but it has the shoes 26 and 28 in place so that the wheel is ready for mounting as received from the factory. I f Having. thus described my inventiton, what I claim as new and desire to secure by Letters Patent is:

1. A grinding wheel comprising abrasive segments arranged in the form of an annulus having. a peripheral grinding, face, a peripheral supportingface and side faces, periph erally spaced abrasive lugs projecting from the side faces which form beveled clamping] shoulders, and clamping membersarranged on each side of the annulus in engagement with the peripheral supporting face and pro vided with portions engaging said shoulderswhich are adapted to ad ustably secure the, wheel segments in osition. 2. A grinding w sive annulus having outer and inner per1ph-' eral faces, side facesand an inner reduced portion providing a recess whereby. a clamping plate may be mountedwithin thewheel, spaced projecting lugs of abrasive onthe. sides of the reduced ortion which form beveled clampmg shoul ere, andjclamping plates 1 eel comprising an abrahaving a surface engaging said inner. face,

each of said segments havin an abrasive portion projecting from each side face which has a clamping shoulder thereon, peripherally spaced from the clamping shoulders on the adjacent segments, and means for clamping against said shoulders and holding the segments securely against said supporting surface. I

4. A grinding wheel comprising an abra sive annulus which has a'peripheral grinding I face,'side faces and an. innerreduced portion providing a recess wherein a clamping plate may be mounted, said of *abrasive projecting rom each side face and shoes thereon adaptedto form clamping shoulders for mountingthe annulus on a suitable support. v

5. A grinding wheel comprising abrasive segments arranged in the form of an annulus, each having a peripheral grinding face, side faces and an inner reduced portion forming a recess, said portion being provided with lugs of abrasive projecting from each side face, a shoe of metal on eacli lug and clamp ing members arranged one oneach side of the annulus in said recess having surfaces engaging and seating against said shoes which secure the segments in position.

6. A grinding wheel comprising an abrasive annulus having a peripheral grinding faceand spaced-lugs forming clamping shoulders, and plates slotted to receive and surround the projecting lugsa'nd engage the clamping shoulders, said parts being so constructed and arranged that upon drawing the plates together the abrasive annulus is clamped in position. 7. Agrinding wheelcomprisingaplurality ofoabrasiv segments arranged in the form of which project an annulus having inner and outer periph eral faces and two side faces, projecting lugs of abrasive on each side "face, a shoe on each grojecting' lug forming a clamping shoullug and engaging said shoe and a surface supporting the inner face of each segment, andmeans for drawing the clamping plates together to secure said annulus in position.

8. A grinding wheel comprising an annulus. of bonded abrasive segments having a substantially continuous'per'ipheral grindlng face, side faces, and peripherally spaced lugs from the side faces and form clamping shoulders adapted for rigidly seface, side faces, an inner ortion having lugs a clamping plate on each side of the an; nulus having a portion projecting over the curing-the annulus upon a rotatable support. 9. grinding wheel comprising an annulus of bonded abrasive segments having a substantially continuous peripheral grinding reduced portion providing a recess on the side of the wheel with in which a supporting plate may be mounted,

and peripherally spaced lugs integral with the side face Within the recess which projects outwardly and forms clamping shoulders adapted for rigidly securing the annulus upon a rotatable support.

10. A grinding wheel comprisingabrasive which has a peripheral grinding face and'side faces, said annulus having projecting portions of abrasive on each of its opposite sides, each portion having an accurately shaped shoe integral therewith whichforms a clamping shoulder on one surface thereof adapted to provide a means for exactly positioning said annulus upon a rotatable support.

11. .A grinding wheel comprising a plurality. of abrasive segments arranged as an annulus having a peripheral grinding surface andtwo side faces, each segment having peripherally spaced abrasive lugs projecting from its opposite sides which form clamping shoulders, and a cementitious filler between the adjacent segments uniting the same into a unitary structure.

, segments arranged in the shape of an annulus 12. A grinding wheel comprising a pluralityof abrasive segments mounted to form an annulus having a peripheral grinding surface and two side faces, each segment having abrasive lugs projecting from each side'face, a shoe on each lug which has a beveled surface forming aclamping shoulder, and a filler of metal flowed into the crevices between the segments and the surface pores which unites the segments into an integral wheel structure.

13. A grinding wheel comprising-a plurality of abrasive segments arranged to form an annulus having inner and outer peripheral faces and side faces, projecting abrasive lugs on each side face formin clampin shoulders, a cementitious fillerdmtween t e adja cent faces of the segments which unite them into an integral unitary structure, and a shoe on the inner peripheral face of each segment constituting a supporting surface.

14. A grinding wheel comprising a plurality of abrasive segments arranged to form an annulus having innerand outer peripheral faces, projecting abrasive lugs on each side face, adjacent faces of the segments uniting them into an. integral unitary structure, a shoe on the inner'periphera'l face of each segment constituting a supporting surface, and a shoe of'metal integral with each projecting abrasive lug to form a clamping shoulder.

15. An abrasive segment'arranged to be assembled with others to form' an annulus a cementitious filler between-the comprising a body of bonded abrasive grains having a partially cylindrical grinding surface and a concentricinner supporting surface, substantially parallel side faces, each of which has a lug of abrasive projecting therefrom and forming a clamping surface, whereby said segment may be exactly positioned upon its support, said lug being so located that it will be spaced peripherally from the lug of an adjacent segment.

16. An abrasive segment comprising a body of bonded abrasive grains having a partially cylindrical grinding surface, a concentric inner supporting surface and substantially parallel recessed side faces having spaced lugs of abrasive projecting therefrom, and accurately shaped metal shoes integral with said projecting lugs which form clamping surfaces whereby said annulus may be e2;- actly positioned upon its support.

17. An abrasive segment comprising a body of bonded abrasive grains having a convex outer grinding face and a concave inner supporting face which is adapted to be mounted with similar bodies to form an annulus, substantially parallel side faces having peripherally spaced lugs of abrasive projecting therefrom, a shoe on the inner concave face constituting a supporting surface, and accurately shaped metal shoes integral with said projecting lugs forming clamping surfaces thereon.

Signed at Worcester, Massachusetts, this 28th day of June 1927.. I

THUR-E LARSSON. 

